Nolan was in the middle of shooting Inception by mid 2009, but he did say in interviews that he had a general outline for TDKR before Inception as they (him and Emma) said they knew Bane was the villain before shooting Inception. Which must mean the writer is talking about late 2009 when Nolan was in post for Inception. Perhaps then they made further developments on Batman and the ideas for MOS germinated from Goyer. But I still don't see anything beyond that phone call for Nolan between post for Inception, promoting Inception and getting ready for pre-production on Rises.

During the Sucker Punch press tour (Where 90% of the questions revolved around MoS) Snyder spoke openly about him constantly calling Chris Nolan to run things by him, to which he'd reply "That sounds awesome" (As I've said before, it's safe to say he's paraphrasing here). Also, in the article from Empire, Snyder talks about working with him. The part I remember best was when he said Nolan wouldn't let him do things just because 'it was cool', but they had to a have a specific, logical function to the world/story.

It's safe to at least hypothesize that during these conversations, Nolan may have contributed ideas of his own. It was when shooting started on TDKR that he backed off a lot, then completely when they started shooting MoS.

Again, a lot of this is hypothetical, but it's more supported and more likely than Nolan JUST pitching the movie.